Molecule Derived Synthesis of Nanocrystalline YFeO3 and Investigations on Its Weak Ferromagnetic Behavior

• Published in: Chemistry of materials 2004-05, Vol.16 (10), p.1906-1913
• Main Authors: Mathur, Sanjay, Veith, Michael, Rapalaviciute, Rasa, Shen, Hao, Goya, Gerardo F, Martins Filho, Waldir L, Berquo, Thelma S
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; General and physical chemistry; Physicochemistry of polymers; Physics
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm0311729

A new Y−Fe alkoxide, [YFe(OPri)6(PriOH)]2, is used in the sol−gel process to obtain the orthoferrite, YFeO3. The Y/Fe stoichiometry (1:1) and Y−O(R)−Fe chemical links in the single molecular precursor kinetically control the formation of metastable YFeO3 which is otherwise difficult to prepare due to the easy formation of the garnet composition, Y3Fe5O12. TG/DTA analysis showed the crystallization of YFeO3 at 680 °C, which was confirmed by XRD data. The powders obtained were nanocrystalline (TEM) and the only crystalline compound present between 600 and 1300 °C was monophasic YFeO3. The absence of garnet and other iron-containing residual phases observed in previous studies was confirmed by temperature-dependent Mössbauer and magnetization measurements. The magnetization data support a weak ferromagnetic behavior and reveal low- and high-field regimes in M−T and M−H curves, corresponding to magnetocrystalline and antisymmetric-exchange anisotropy, respectively.